drivers/gpio/gpio-em.c

Source file repositories/reference/linux-study-clean/drivers/gpio/gpio-em.c

File Facts

System
Linux kernel
Corpus path
drivers/gpio/gpio-em.c
Extension
.c
Size
9440 bytes
Lines
388
Domain
Driver Families
Bucket
drivers/gpio
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct em_gio_priv {
	void __iomem *base0;
	void __iomem *base1;
	spinlock_t sense_lock;
	struct platform_device *pdev;
	struct gpio_chip gpio_chip;
	struct irq_chip irq_chip;
	struct irq_domain *irq_domain;
};

#define GIO_E1 0x00
#define GIO_E0 0x04
#define GIO_EM 0x04
#define GIO_OL 0x08
#define GIO_OH 0x0c
#define GIO_I 0x10
#define GIO_IIA 0x14
#define GIO_IEN 0x18
#define GIO_IDS 0x1c
#define GIO_IIM 0x1c
#define GIO_RAW 0x20
#define GIO_MST 0x24
#define GIO_IIR 0x28

#define GIO_IDT0 0x40
#define GIO_IDT1 0x44
#define GIO_IDT2 0x48
#define GIO_IDT3 0x4c
#define GIO_RAWBL 0x50
#define GIO_RAWBH 0x54
#define GIO_IRBL 0x58
#define GIO_IRBH 0x5c

#define GIO_IDT(n) (GIO_IDT0 + ((n) * 4))

static inline unsigned long em_gio_read(struct em_gio_priv *p, int offs)
{
	if (offs < GIO_IDT0)
		return ioread32(p->base0 + offs);
	else
		return ioread32(p->base1 + (offs - GIO_IDT0));
}

static inline void em_gio_write(struct em_gio_priv *p, int offs,
				unsigned long value)
{
	if (offs < GIO_IDT0)
		iowrite32(value, p->base0 + offs);
	else
		iowrite32(value, p->base1 + (offs - GIO_IDT0));
}

static void em_gio_irq_disable(struct irq_data *d)
{
	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);

	em_gio_write(p, GIO_IDS, BIT(irqd_to_hwirq(d)));
}

static void em_gio_irq_enable(struct irq_data *d)
{
	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);

	em_gio_write(p, GIO_IEN, BIT(irqd_to_hwirq(d)));
}

static int em_gio_irq_reqres(struct irq_data *d)
{
	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);
	int ret;

	ret = gpiochip_lock_as_irq(&p->gpio_chip, irqd_to_hwirq(d));
	if (ret) {
		dev_err(p->gpio_chip.parent,
			"unable to lock HW IRQ %lu for IRQ\n",
			irqd_to_hwirq(d));
		return ret;
	}
	return 0;
}

static void em_gio_irq_relres(struct irq_data *d)
{
	struct em_gio_priv *p = irq_data_get_irq_chip_data(d);

	gpiochip_unlock_as_irq(&p->gpio_chip, irqd_to_hwirq(d));
}


#define GIO_ASYNC(x) (x + 8)

Annotation

Implementation Notes